Stave Bunting Plant Response to Fire REM 456

Stave Bunting Plant Response to Fire REM 456 - Integrated Rangeland Management

Depends on fire history of ecosystem Ecosystems with less frequent fire ◦ Tundra ◦ Deserts Cold Desert Hot Desert Jen Peterson Tundra K. Launchbaugh Photo by Daniel R. Rathrauff, USGS Plant success depends on ability to compete or adapt to climate…. Not necessarily able to survive fire

Depends on fire history of ecosystem Ecosystems evolves with frequent fire ◦ Grasslands ◦ Dry Forests photogallery. nrcs. usda. gov Plants adapted to avoid or tolerate fire. ◦ Plants may even benefit fire: ◦ Germination – seeds scarified by fire ◦ Create Habitat – removing existing plants & releasing nutrients.

Fire characteristics Plant mortality Severity = impacts of heat from fire ◦ Fire that reaches 120 to 130 F typically kills plant tissue. Residency time = how long fire burns in area ◦ Even low temperature fire can be damaging if it moves slowly across the landscape Fire behavior and landscape patterns ◦ Patchy fire can recover rapidly because seeds may be available in unburned areas ◦ Widespread fires can foster erosion and reduce seeds available in area. Season of fire and phenological stage of plants is important. ◦ Buds and leaves are more sensitive to fire when they are metabolically active.

Plant Adaptation to Fire - Avoidance Fuel characteristics affected by plant structure: ◦ Fuel Load = amount of live and dead fuel (weight/unit area) photogallery. nrcs. usda. gov ◦ Fuel Size Class = Dead fuels divided into size classes based on diameter: (e. g. , < 1/4 -inch, 1/4 to 1 -inch, 1 to 3 inches, and > 3 inches)

Plant Adaptation to Fire - Avoidance ◦ Fuel Bed Depth = the depth of surface fuel layer i. e. , the average height of surface fuels contained in the combustion zone of a spreading fire front S. Bunting

Plant Adaptation to Fire - Avoidance ◦ Packing Ratio = compactness of fuel bed

Plant Adaptation to Fire - Avoidance ◦ Bulk Density = the actual fuel weight per unit. WEIGHT per unit area ÷ fuel bed DEPTH

Plant Characteristics affect Fire Severity of fire affected by plant characteristics: S. Bunting Sheri Hagwood. Bureau of Land Management Jen Peterson ◦ Morphological = Fire resistant bark ◦ Chemical = chemicals that reduce probability of combustion ◦ Waxy and stiff surfaces can reduce flammability ◦ Volatile compounds can increase flammability

Plant Characteristics affect Fire Severity ◦ Growth form ◦ Bunchgrasses vs Sodgrass Crested Wheatgrass vs Western Wheatgrass Jen Peterson K. Launchbaugh

Plant Characteristics affect Fire Severity ◦ Growth form ◦ Strong vs Dispersed Bunchgrass Idaho Fescue Jen Peterson vs Bluebunch Wheatgrass Jen Peterson

Plant Adaptation to Fire - Tolerance Growth after fire depend on: Location of buds ◦ Below ground buds – The upper 1 inch of soil typically only experiences a very brief increase in temperature during a fire on rangelands photogallery. nrcs. usda. gov

Plant Adaptation to Fire - Tolerance ◦ Basal sprouts (rabbitbrush or horsebrush) ◦ Rhizomes and other adventitious sprouting (pinegrass) ◦ Also affected by season – when are growing points elevated?

Plant Adaptation to Fire - Tolerance Fire-adapted seeds ◦ Hard seed coating that is scarified by fire ◦ Serotinous cones i. e. , logdepole pine ◦ Seeds protected in canopy i. e. , ponderosa pine

Plant Adaptation to Fire - Tolerance Fire-adapted seeds (continued) ◦ Seeds that are wind dispersed i. e. , fire weed (Epilobium angustifolium) Julie Hankins ◦ Seed vulnerability is typically dependant on seed position and amount of moisture seeds contain

Plant Adaptation to Fire - Tolerance Carbohydrate Allocation Patterns ize l i b o m rs. y e l h p t im n o s an tha c ts tter n la be p e ces m So sour re Julie Hankins

Other Factors Affect Plant Response ◦ Post-Fire Weather ◦ Post-Fire Animal Use ◦ Plant Competition

Summary Questions What time of year is fire most damaging to grasses and why? What time of year is fire most damaging shrubs and why?

How Fire differs from Grazing as a Plant Disturbance Fire Grazing

Fire Grazing Not selective for specific plants Selects palatable over unpalatable Removes dead and live tissue Live tissue preferentially removed Produces heat No heat produced Recycles nutrients in inorganic form Recycles nutrients in organic (feces) and inorganic (urine) forms Nutrients in a relatively even layer across the landscape Nutrient in patches Patchiness on landscape scale Patchiness on plant-scale Most likely in dry-hot season Occurs year round Generally reduces seed viability, though some seeds require fire to be viable Generally reduces seed viability though some seeds require consumption to be viable

Stave Bunting Plant Response to Fire REM 456 - Integrated Rangeland Management